[Tanoc]

From experience, no online used marketplace seems to be immune from price manipulation or inflation. KBB is used as a reference tool to find a starting point for vehicle prices, but the only way to really know how much they cost is going through multiple websites to see. I'd suggest scraping data from Cars.com, eBay Motors, Craigslist, Facebook Marketplace, Autolist, and Cargurus.

For a starting point I'd have it look at vehicles from 2012 or newer. This should prevent "classic" or newly collectible vehicles from spiking the data. Secondly, be aware that Craigslist prices on the front of the ad are often listed as fake numbers such as "0$" or "12345$" with the actual soft or hard price contained within the ad's body of text. Facebook Marketplace can be much worse about this, and much more manipulative with the number of fake listings, so check for duplicates or suspiciously low prices to prevent spiking the data. eBay Motors has a quirk shared with eBay, where they have both an auction price and a Buy It Now price. The only reliable way to gauge prices there would be using Buy It Now listings.